We use the formalism of quantum hydrodynamics [1]}, [2]}, [3]}, [4]} to describe Bose-Fermi mixtures. Such a treatment
was already disscussed many years ago by Ball et al. in the context of the oscillations of electrons in a many-electron atom induced by ultraviolet and soft X-ray photons [5]}. They assumed the velocity field of electrons is irrotational. In our study we follow the same reasoning and apply quantum hydrodynamic equations both for fermionic and bosonic clouds in a droplet.
